Skip to main content

Columbia Water-Meal

Wolffia columbiana

Last reviewed: August 2026

Columbia Water-Meal (Wolffia columbiana)
Photo: Derek / Wikimedia Commons (CC BY 4.0)

Toxicity unknown

Columbia Water-Meal (Wolffia columbiana) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.

Light

part sun

Water

high

Size

0.01"–0.1" H × 0.01"–0.1" W

Bloom

N/A

Native to

AL, AR, CA, CO and 35 more states

Before you buy

Your city may pay you to plant this

Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 445 programs across 44 states, each with a link to the provider and the date we last checked it.

Find rebates in your area

Browse plants for this ecoregion

Coast RangeMarine West Coast ForestCentral California Foothills and Coastal MountainsHigh PlainsCentral Great PlainsCross TimbersSouth Central PlainsOzark HighlandsCentral Irregular PlainsGreat PlainsWestern Corn Belt PlainsNorthern Lakes and ForestsNorth Central Hardwood ForestsDriftless AreaSoutheastern Wisconsin Till PlainsCentral Corn Belt PlainsEastern Corn Belt PlainsSouthern Michigan/Northern Indiana Drift PlainsNortheastern HighlandsNortheastern Coastal ZoneNorthern Allegheny PlateauErie Drift PlainMiddle Atlantic Coastal PlainNorthern PiedmontSoutheastern PlainsRidge and ValleyInterior PlateauInterior River Valleys and HillsMississippi Alluvial PlainSouthern Coastal PlainEastern Great Lakes LowlandsSouthern California/Northern Baja Coast

Wolffia columbiana is the world's smallest flowering plant, measuring less than one-tenth of an inch across. This tiny aquatic plant floats on the surface of ponds, lakes, and slow-moving water bodies. It reproduces rapidly by budding and can form dense green mats on water surfaces.

In an HOA neighborhood

Columbia Water-Meal takes more care to keep looking intentional in a front yard. Maintenance level: low. Consider it for backyard or mid-zone beds rather than the street edge.

  • Requires permanent water feature which most HOAs restrict
  • Can appear as algae or scum on water surface
  • Not suitable for typical residential landscaping

Wildlife value

This microscopic plant provides food for waterfowl, fish, and aquatic invertebrates. While it rarely flowers, it serves as an important component of aquatic food webs.

Common questions

How much sun does Columbia Water-Meal need?
Columbia Water-Meal grows best in part sun conditions.
Where is Columbia Water-Meal native?
Columbia Water-Meal (Wolffia columbiana) is native to AL, AR, CA, CO and 35 more states, per vouchered herbarium specimen records and regional native plant society lists.
Is Columbia Water-Meal HOA-friendly?
Columbia Water-Meal takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

Native range data from vouchered herbarium specimen records and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

Ready to grow Columbia Water-Meal? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.

Add this plant to your garden
iPhone appAndroid app

Not sure where to start? Take the 2-minute yard quiz